Export/Import tool for OpenCart 1.5.4

i have this problem

Fatal Error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 32 bytes) in /home/lelo4me/public_html/system/PHPExcel/Classes/PHPExcel/Shared/OLERead.php on line 314

this is line 314

return ord($data[$pos]) | (ord($data[$pos + 1]) << | (ord($data[$pos + 2]) << 16) | $_ord_24;